It is often necessary, or desirable, to maintain one component of a multi-component product, e.g., a shaving cream, separate from other components of the product or from some part of the container in which the product is stored.
For example, the components of the product may react with each other when mixed, and it may be desired to prevent this reaction from occurring until the product is dispensed.
Moreover, in some cases it is important to keep one component of a multi-component product from contacting the container holding the product due to the reactive nature of the particular component, e.g., if the component reacts with metals and the container is metal or includes metal parts such as springs.
Other reasons for maintaining one component separate from other components include aesthetic reasons, e.g., to provide a xe2x80x9cstripexe2x80x9d of one color against a background of another color when the product is dispensed.
Various systems have been used in the past to package and dispense products containing two components so that the components are separated during storage and mixed during or just prior to dispensing, e.g., as disclosed in U.S. Pat. Nos. 3,241,722 and 3,454,198.
The present invention provides systems for dispensing multi-component products. Preferred systems maintain one component of the product completely separate from other components until the product is dispensed. Because the components do not contact each other until the instant that the product is dispensed, products including highly reactive components can be effectively dispensed. The systems are easily filled using mass production techniques, and preferred systems include a dispensing valve assembly that has a convenient modular design, allowing it to be easily assembled into the dispensing system.
In one aspect, the invention features a pressurized dispensing system for dispensing a multi-component product, including (a) an outer body defining a first chamber constructed to contain a first component of the product; (b) an inner container, disposed within the body, defining a second chamber constructed to contain a second component of the product and maintain the second component separate from the first component; (c) a dispensing head, in fluid communication with the first and second chambers, through which the product is dispensed; and (d) a modular valve assembly, including a valve constructed to move between a closed position, in which the first and second chambers are sealed, and an open position, in which the first and second components flow simultaneously from the first and second chambers to the dispensing head.
In some implementations, the modular valve assembly includes a valve cup and a valve body, together defining a chamber, and, within the chamber, a valve subassembly and an upper valve seal. The valve subassembly may include a valve stem including a first valve portion for sealing against the first valve seal to seal the first chamber and a second valve portion for sealing against the second valve seal to seal the second chamber, a lower valve seal, and a spring for biasing the valve stem towards its closed position. Preferably, the valve stem is a single unitary member, and is a female stem.
In another aspect, the invention features a method of filling components into a pressurized dispensing system for dispensing a multi-component product, including (a) placing an inner, flexible container within an outer container so that open ends of the inner and outer containers are adjacent; (b) mounting a valve assembly in sealing engagement with the open ends of the containers; and (c) delivering the components into the inner and outer containers through the valve assembly.
In a further aspect, the invention features a method of assembling a dispensing system for dispensing a multi-component product, including (a) mounting an inner container in fluid communication with a modular valve assembly; (b) inserting the inner container and valve assembly into an outer body; (c) sealingly joining a rim portion of the modular valve assembly to a rim portion of the outer body; (d) forming a sealed canister comprising the outer body and the valve assembly; and (e) pressurizing the sealed canister.
In yet another aspect, the invention features a method of filling components into a pressurized dispensing system for dispensing a multi-component product, including (a) placing an inner flexible container, and an outer flexible container within an outer rigid container so that open ends of the inner and outer flexible containers and the outer rigid container are adjacent; (b) mounting a valve assembly in sealing engagement with the open ends of the containers; and (c) delivering the components into the inner and outer flexible containers through the valve assembly.
In some implementations, a propellant is charged to the space between the outer flexible container and the outer rigid container prior to step (c). The method may also include evacuating the inner and outer flexible containers, preferably after charging the propellant and prior to step (c).
The term xe2x80x9cpressurizedxe2x80x9d, as used herein, is intended to encompass both pressurization as a result of a propellant and pressurization resulting from other causes, e.g., a mechanical force applied by a spring.
Other features and advantages will be apparent from the following description of a presently preferred embodiment, and from the claims.